Everything Science Forum

http://www.spaceflightnow.com/news/n0403/25messenger/

In interplanetary missions this means a huge penalty: in this cause an arrival delay of 2 years! :-\

status report:

http://www.spaceref.com/news/viewsr.html?pid=13046

another (small) delay

http://www.spaceflightnow.com/delta/d307/status.html

From that last link:

Repeated delays in launching a Boeing Delta 2 rocket carrying a Global Positioning System satellite this month at Cape Canaveral have created a ripple effect by prompting NASA to postpone by three days the liftoff of the MESSENGER space probe to orbit Mercury.

The GPS mission flew from the same launch pad that MESSENGER must use, creating the schedule crunch. Technical troubles and then a stretch of bad weather kept the Air Force Delta 2 mission grounded for more than two weeks.

At least the GPS is something the public knows full well about and understands. The launch window for MESSENGER may be tricky, but in general it must be hard for NASA to prioritize work for a space science vehicle launch over that for a GPS satellite.

http://www.spaceref.com/news/viewsr.html?pid=13268

Here's a site dedicated to the Messenger mission. It has a lot of information, presumably legitimate.

http://messenger.jhuapl.edu/

If you hit the link on the solar cells, you find this:

To run MESSENGER's systems and charge its 23-ampere-hour nickel hydrogen battery, the panels, each about 1.5 meters (5 feet) by 1.65 meters (5.5 feet), will support between 385-485 watts of spacecraft load power during the cruise to Mercury and 640 watts during the science orbit. The panels could produce more than two kilowatts of power near Mercury, but to prevent stress on MESSENGER's electronics, onboard power processors take in only what the spacecraft actually needs.

The panels are 67 percent mirrors (called optical solar reflectors) and 33 percent triple-junction solar cells, which convert 28 percent of the sunlight hitting them into electricity. Each panel has two rows of mirrors for every row of cells; a total of 648 cells and 1,296 mirrors per panel. The small mirrors reflect the Sun's energy and keep the panel cooler. The panels also rotate, so MESSENGER's flight computer will tilt the panels away from the Sun, positioning them to get the required power while maintaining a normal surface operating temperature of about 150 degrees Celsius, or 302 degrees Fahrenheit.

There is solar power galore available where Messenger is going!  :o Contrast its situation with that of the Cassini/Huygens spacecraft.

I believe it is the official MESSENGER website. :)

The Sun is the problem at Mercury. Not too less, but too much! Most electronics work at room temperature!

I'd like to know what is meant by "triple-junction solar cells". I am guessing it is some kind of semiconductor structure to more efficiently utilize the absorbed energy, or to allow operation at higher temperatures. That absorbed radiative power that doesn't get converted to electricity ends up as heat, which the panels don't need more of.

Good that the recent robot spacecraft missions to Mars and Mercury have avoided the plutonium power generator controversy, which sparked lots of protests when Cassini was launched.

Edit: Addition-I found this excellent description about these solar cells using the Google search engine:

http://www.emcore.com/assets/photovoltaics/Triple.pdf

Launch date is getting nearer...

http://www.spaceref.com/news/viewsr.html?pid=13349

Dont you feel mercury mission is not need of the  day?Moon and mars are more important.

well..at least us spaceflight geeks are enthusiastic. Mercury is only very poorly explored. Plenty of interesting questions remain.

http://messenger.jhuapl.edu/why_mercury/index.html

Can we terraform it or use its resources?Can use its minerals?I mean there seems no practical side.Nor can we expect anythingunthinkable about mercury.Of course w may know unexpected things,I dont know.But not much in th expectation range.

Improving knowledge of our solar system is a good cause in its own. Why do we look at distant galaxies when we can never reach them? Who cares if the universe will collapse in a couple of billion years?

http://www.spaceref.com/news/viewpr.html?pid=14590

"NASA is Sending a MESSENGER to Mercury "

We are anxiouly waiting for mercury to go on august 2.It will bea new horizon in inner solar system.

Mercury will be a good tourist spot in fu.ture as in its pole it never sees sun and ever cool

next stop: the Launch pad!

http://www.spaceref.com/news/viewsr.html?pid=13425

So WE are due to flyby iron planet flybye soon .Thrilling.

http://www.wired.com/news/space/0,2697,64330,00.html?tw=wn_tophead_2

Nearly 30 years after sending the Mariner 10 spacecraft on a few flybys past Mercury, NASA is set to return to the hot planet -- this time, with the intention of staying awhile.

How possibl it can stay a while?Its a flyby.

no it's not

http://messenger.jhuapl.edu/the_mission/mission_design.html

It will orbit for a while.

a preview story
http://www.csmonitor.com/2004/0729/p13s01-stss.html

launch status:
http://www.spaceref.com/news/viewsr.html?pid=13496

Launch is Monday!

Mercury is nearest planet.It is natural for it to too hot.Oasis is icepoint if they exist.Eagerly waing to know if mecury has ice.

spaceflightnow's preview story:
http://www.spaceflightnow.com/delta/d307/040729preview1.html

The motion of sun retrogade catches imagination .Sun double size in earth ,burning and sky is black as there is no atmosphere the culprit who obstructs us,from seeing stars nicely.I feel like landing in messeger.I shal be the first man to hermes. HA HA.

I heard on the radio this morning (Monday, August 2) that Messenger missed its launch window. Clouds over the launch site. The story said that its launch window was only 12 seconds long!

(Edit: addition) Here is the story on space.com

http://www.space.com/missionlaunches/messenger_scrub_040802.html

there will be another chance today

LAUNCH!!!

Yes! Hooray! MESSENGER is on its way at last! Here's another space.com article:

http://www.space.com/missionlaunches/messenger_launch_040803.html

Cape Canveral launch officials applauded as MESSENGER’s Delta 2 booster sent the spacecraft on its way.

Four minutes into the flight, the spacecraft-rocket combo shed its first stage and ignited its second stage for a four-minute burn to reach orbit. After a 37-minute coast phase, MESSENGER’s Delta 2 booster again fired its second stage for a three-minute burn. The spacecraft’s third stage also made a short, two-minute maneuver before MESSENGER separated from its rocket and began its trip to Mercury about 59 minutes after launch.

MESSENGER then loosed its two solar panels to generate power and switched off its batteries. The event marked the end of the first leg of MESSENGER’s five billion-mile journey to Mercury. Over the next seven years, the spacecraft will swing by the Earth once, Venus twice and Mercury three times before reaching a final orbit around the small planet.

After a year of science observations, the spacecraft will have completed its primary mission.
 
"The mission ends with a whimper," McNutt said, adding MESSENGER’s fuel tanks were budgeted to provide enough propellant for a single year around Mercury. "By about 2015 or 2016, gravity will crash [MESSENGER] into the surface of the planet."

I was a little surprised at how much energy must be expended to get to Mercury. On the other hand, it takes a lot of energy to send a probe into the sun, and I guess a lot of gravitational energy must be shed in order to get something into orbit around something as close to the sun as Mercury. It's going to be a very roundabout trip, as was Cassini. Here's another part of the space.com article:

"Mercury is very hard to get to," explained MESSENGER science team member Ralph McNutt, from the Johns Hopkins University Applied Physics Laboratory, during the Aug. 2 launch attempt. "To get there, the MESSENGER spacecraft is about 55 percent fuel, about the same amount as the Cassini spacecraft to Saturn."

By MARCIA DUNN, AP Aerospace Writer

The journey will take 6 1/2 years, covering nearly 5 billion miles on a roundabout ramble through the inner solar system. The probe should reach Mercury by March 2011, then spend a year gathering data.

Scientists want to know how the planet turned out the way it did, and whether the perpetually dark craters at the poles hold ice. Anything scientists can learn about how Mercury formed will shed light on the origins of Venus, Earth and Mars, each one very different.

The Messenger mission is part of NASA's bargain-focused Discovery program — $427 million for the launch and all the scientific analysis years later in a mission devised by Johns Hopkins University.

Scientists have been yearning to study Mercury up close ever since Mariner 10 zoomed by three times in the mid-1970s. If all goes well, Messenger will be the first spacecraft to orbit that planet.

Because it can't carry enough fuel, Messenger cannot fly straight to Mercury. So it will fly once past Earth, twice past Venus and three times past Mercury for gravity assists — and make 15 loops around the sun — before slowing enough to slip into orbit around the small, hot planet.

The heat encountered once in orbit will be the equivalent of 11 suns beating down on Earth, about 700 degrees. But its instruments will operate at room temperature, protected by a custom-built ceramic-fabric sunshade just one-quarter of an inch thick. All Mariner 10 had was a quaintly old-fashioned umbrella.

AP photo (1), Reuters photo (2)

update....

http://www.astrobio.net/news/modules.php?op=modload&name=News&file=article&sid=1313&mode=thread&order=0&thold=0

Lets talk of present position in2005 almost.

still on its way for a while...

We are to wait for six years or so.

update

http://www.mercurytoday.com/news/viewsr.html?pid=15384

http://www.mercurytoday.com/news/viewsr.html?pid=15468

another update

"Staring at a Supernova "

very cool movie of the earth receding, whilst spinning

http://www.planetary.org/news/2005/messenger_flyby_movie_0826.html

Hi-res version (6 megs!)
http://messenger.jhuapl.edu/the_mission/images/flyby_images/mdis_depart_anot.mpeg